The invention relates to an arrangement for the treatment of high-polymer articles with boiling acrylic acid and solutions thereof. Of particular interest to the invention is an arrangement for the grafting of acrylic acid to high-polymer articles, especially textile articles which contain polyester or polyamide fibers, which have been previously irradiated with ionizing radiation.
It is known to subject high-polymer articles such as, for instance, webs, to irradiation with a view towards modifying their properties. The radiation used is an ionizing radiation in that it causes the formation of ions or the like in the high-polymer material.
A modification of the properties of the thus-irradiated (pre-irradiated) articles, particularly articles made of polyester fibers, is obtained by grafting the pre-irradiated articles with acrylic acid. This may be accomplished by treating the articles with diluted, aqueous acrylic acid at a temperature of about 100.degree. C for some period of time (of the order of 30 minutes). During the treatment, evaporation of the acrylic acid occurs and the evaporated acrylic acid must be condensed in the grafting apparatus. As a result, a strong build-up of acrylic acid homopolymer occurs at the liquid-gas interfaces of the apparatus. This, in turn, makes it necessary to frequently disassemble such an apparatus in order to permit mechanical removal of the homopolymer.
Attempts to overcome this problem have involved the use of stabilizers and, in particular, the industrially used stabilizer hydrochinone monomethylether. It has, however, been demonstrated that this stabilizer does not sufficiently suppress the homopolymer formation in boiling, aqueous acrylic acid.
It is also known that copper is a stabilizer for acrylic acid, that is, that copper reduces the homopolymer formation.
There is, however, no apparatus known wherein the formation of acrylic acid homopolymer from boiling acrylic acid and its solutions can be satisfactorily suppressed.